The invention relates to a fastening element, in particular for connecting two parts in a chassis, which fastening element has a central axle on which at least two support elements of damping material are arranged at an axial distance from one another.
Fastening elements of this type are required in order, for example in vehicle wheel suspension systems, to secure two parts, which execute certain movements in operation, relative to each other. Fastening elements of this type are also referred to as coupling rods. They ensure that the parts which are to be secured relative to one another are held in a manner low in vibrations. An example of a coupling rod is shown in U.S. Pat No. 4,944,523. As shown therein, the coupling rod is provided with a central axle in the form of a steel bolt 112. See U.S. Pat. No. 4,944,523, Col. 5, 11. 8-16. The coupling rod of U.S. Pat. No. 4,944,523 is also provided with support elements molded of an elastomeric material, referred to as “grommets.” U.S. Pat. No. 4,944,523, Col. 5, 11. 35-45.
Consequently, in previously known solutions, a central metal axle is provided onto which support elements of rotationally symmetrical design are pushed. In this case, the support elements are shaped in such a manner that two support elements can secure between them a part which is to be retained. The support elements here are composed of a suitable plastics material such that adequate damping behaviour can be obtained. The use of polyurethane has proven successful here.
In this case, limits which are defined by the forces to be absorbed are to be taken into consideration both in the selection of material for the support elements and in the formation thereof.
It has emerged that coupling rods of the type mentioned at the beginning still leave something to be desired in this regard. In particular, it has been found to be negative that undesirable effects in the form of bending moments occur if the fastening element has to be dimensioned in such a manner that it can absorb high retaining forces.